One type of belt used in the manufacture of fibrous webs convertible into tissue products, such as paper towels, facial tissues, toilet tissues, and napkins, are through-air drying belts. Through-air drying belts are often woven from yarns to provide a belt having a three dimensional surface topography and variable permeability. Examples of woven through-air drying belts are disclosed, for example, in U.S. Pat. Nos. 6,998,024 and 7,611,607. Such fabrics may be woven such that they have a textured sheet contacting surface comprising substantially continuous machine-direction ridges separated by valleys. The ridges may be formed of multiple warp strands grouped and stacked together to a height from 0.5 to about 3.5 millimeters. The stacked warp strands provide the sheet contacting surface with a three dimensional topography, which is desirable for molding and shaping the nascent tissue web, but alter the permeability of the fabric such that there are regions of high permeability and low permeability. Further, the height of the ridges is limited by the conformability of the nascent web.
To overcome limitations of woven papermaking belts, tissue makers have developed composite belts having a framework joined to a fluid-permeable reinforcing layer such as, for example, a woven structure. The framework may be resinous, such as those disclosed in U.S. Pat. Nos. 4,637,859, 5,628,876 and 6,358,594, or they may be a silicone, or the like, such as that disclosed in U.S. Pat. No. 9,657,444. The advantage of such fabrics is that the frameworks may take any number of different patterns, and may be continuous, semi-continuous, comprise a plurality of discrete protuberances, or any combination thereof. Further, the framework, which is independent of the reinforcing layer and generally not constrained by the limitations of weaving technology, extends outwardly from the reinforcing layer and may define apertures that may receive and structure the nascent web as it is dried. While the framework may provide benefits over fabrics consisting essentially of woven yarns, such composite belts have limitations. For example, the prior art methods of manufacturing composite through-air drying fabrics generally result in the framework surrounding the underlying woven yarns, which reduces the permeability of the composite belt and may impede drying of the nascent web.
Accordingly, there remains a need in the art for a papermaking belt and more specifically a through-air drying belt useful in the manufacture of through-air dried tissue products that overcomes the limitations of prior art woven and composite belts. Specifically, there remains a need for a multi-layered belt that is capable of providing the nascent tissue with a wide range of patterns without negatively affecting the tissue making process and more specifically drying of the nascent tissue web.